Study On Microscopic Identification And The Content Of Alkaloids Of 14 Medicinal Plant Species Of Berberis L.

The microscopic characteristics of the powders of stems and leaves of 14 medicinal plant species of the genus Berberis were observed by microscope,and the transection features of their leaves were also observed.Single factor combined with response surface method was used to optimize the extraction process of total alkaloids in the leaves of barberry,and ultraviolet spectrophotometry was applied to determine the total alkaloid contents in both stems and leaves of the 14 species.The contents of five alkaloids(coptisine,epiberberine,jatrorrhizine,jatrorrhizine,berberine and palmatine)in the stems and leaves of the 14 species was determined by ultra performance liquid chromatography.The main results are shown as follows.1、The vascular bundles of the midveins of the leaves are of infinite external toughness,with thick-walled tissues above and below.The number of palisades of the leaves was two for six species,but more than two for other species.The proportion of palisade tissues to mesophylls among the transection of leaves is less than 1/2 for most species,but more than 1/2 in B.deinacantha,and less than 1/3 in B.sanguinea and B.pruinosa.Palisade tissue of 7 species of leaves of Berberis pass through the midrib vascular bundles.There is only one midrib bundle in the leaves of B.gyalaica,B.wilsonae,B.hemsleyana,and B.verruculosa,the remaining ten species have more than one midvessel bundle,only the number of midrib vascular bundles of B.phanera is more than 5.Most of the upper and lower epidermis near the midvein vascular bundles have mechanical tissues,among them,7 species have developed mechanical tissues,only the B.sanguinea and B.taliensis have no mechanical tissues.2、Among the powders of leaves,linear non-glandular hairs,branched non-glandular hairs and spiral vessels are observed in all the 14 species.There exist obvious differences in stone cells,catheter types and calcium oxalate crystal types among the 14 species.Stone cells can be seen in the leaves of 9 species,among which fibrous stone cells are observed in 6 species;there are various types of vessels,besides spiral vessels,pitted,reticulated and annular vessels also exist,the reticulated vessels are observed in 6 species,the ringed and pitted vessels are visible in 3 species;calcium oxalate crystals can be seen in the leaves of 6 species,calcium oxalate solitary crystals are observed in 4 species,and calcium oxalate cluster crystals are found in B.taliensis and B.deinacantha.3、Among the powders of stems,Cork cells,fibers,stone cells,calcium oxalate crystals,pitted vessels,spiral vessels and branched non-glandular hairs are observed in all the 14 species.The cork cells of three species of barberry are mostly connected with stone cells;The phloem fiber walls of the five species are straight,and the rest of the berberis show the wavy curved phloem fiber wall,and the phloem fibers of B.gyalaica Ahrendt and B.amurensis have a thin diaphragm.The morphology of stone cells is diverse,Fibrous stone cells are observed in 9 species,and crystalliferous sclereid can be seen in B.gyalaica Ahrendt and B.pruinosa var.pruinosa.Calcium oxalate solitary crystals are observed in all the 14 species,four species have calcium oxalate cluster crystal.Crystal sheath fibers can be seen in 12 species.4、The contents of total alkaloids in the stems ranged from 7.74 to 29.37(mg·g-1),the highest content was found in B.verruculosa(29.37 mg·g-1),followed by B.wilsonae(23.47 mg·g-1),B.pruinosa(21.19 mg·g-1),B.liophylla(15.40 mg·g-1)and B.taliensis,(14.95 mg·g-1).The contents of total alkaloids in the leaves ranged from 24.73 to 156.14(mg·g-1),the highest content was found in B.lijiangensis(156.14 mg·g-1),followed by B.hemsleyana(92.38 mg·g-1),B.sublevis(90.55 mg·g-1),B.taliensis(78.44 mg·g-1)and B.verruculosa(70.00 mg·g-1).5、Jatrorrhizine,berberine and palmatine exist in both stems and leaves of all the 14 species of Berberis and their contents are relatively high.The species with higher jatrorrhizine content in the stems were B.wilsonae(9.482 mg·g-1),B.verruculosa and B.pruinosa.The B.taliensis(8.032 mg·g-1),B.sublevis and B.hemsleyana had the highest jatrorrhizine content in leaves.The species with the highest content of berberine in the stem was B.pruinosa(9.459 mg·g-1),followed by B.verruculosa and B.taliensis;the relatively high content of berberine in the leaves was B.pruinosa(0.539 mg·g-1).The species with the highest content of palmatine in the stems is B.wilsonae(2.267 mg·g-1),followed by B.pruinosa and B.verruculosa;and the relatively high content of palmatine in the leaves is found in B.sublevis(0.203 mg·g-1).The contents of epiberberine and coptisine in stems and leaves are very low or not detected in both the stems and leaves.6、The leaves of B.pruinosa was sampled to optimize the extraction process of total alkaloids,and the extraction process was optimized as follows:the methanol concentration of the extraction solution is 60%,the solid-liquid ratio is 1:250 g·mL-1，the extraction time is 138 min,and the extraction temperature is 60℃.In addition,an ultra-high performance liquid chromatography method for determination of five alkaloids of Berberis was established.